Work vehicle and method for controlling the work vehicle

Abstract

To further simplify gear shift operation.SOLUTION: A work vehicle comprises: a transmission device which performs transmission of a work vehicle by switching over plural main gear stages and plural auxiliary gear stages; an input section which allows a user to set a value for the main gear stage corresponding to at least one of the plural main gear stages; a storage section which stores a corresponding relation between the auxiliary gear stages and the set value; and a control section which assigns the main gear stage to the value corresponding to the auxiliary gear stage after switching based on the corresponding relation when the auxiliary gear stage is switched.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a work vehicle and a method for controlling the work vehicle.

Background Art

[0002] Work vehicles such as agricultural tractors travel and work in various environments with different ground conditions. In order to be able to cope with various conditions such as the ground conditions, the content of the work, and the required vehicle speed, work vehicles are generally configured to be able to perform multi-stage speed changes. The multi-stage speed change can be realized by a combination of a main transmission and an auxiliary transmission. For example, when the number of auxiliary transmission stages is 3 and the number of main transmission stages is 8, a total of 24 speed changes are possible. The main transmission stage and the auxiliary transmission stage are switched by the user operating an operating tool such as a corresponding lever or button.

[0003] In order to simplify the speed change operation by the user, for example, the combination of the previously used auxiliary transmission stage and the main transmission stage is memorized, and when the auxiliary transmission stage is switched by the user, it is automatically set to the main transmission stage set when that auxiliary transmission stage was previously used. Technologies such as this are utilized. Examples of such technologies are described in, for example, Patent Documents 1 and 2.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] With conventional technologies like those described above, when a user switches the sub-gear, it is not always guaranteed that the main gear will automatically be set to the user's desired gear. If the user wants to set the main gear to a different gear than the one previously used, they must manually switch the main gear. Some users may want the main gear to automatically be set to a specific gear when switching the sub-gear. However, conventional technologies could not accommodate such requests.

[0006] This disclosure provides a work vehicle and a control method thereof that can solve these problems. [Means for solving the problem]

[0007] A work vehicle according to one aspect of the present disclosure includes a transmission that performs gear changes by switching between a plurality of main gears and a plurality of sub-gears; an input unit for a user to set a value for the main gear corresponding to at least one of the plurality of sub-gears; a storage unit that stores the correspondence between the sub-gears and the values; and a control unit that, when the sub-gears are switched, sets the main gear to the value corresponding to the switched sub-gear based on the correspondence.

[0008] The comprehensive or specific embodiments of this disclosure may be implemented by apparatus, systems, methods, integrated circuits, computer programs, or computer-readable non-temporary storage media, or any combination thereof. Computer-readable storage media may include volatile storage media or non-volatile storage media. Apparatus may consist of multiple devices. If apparatus consists of two or more devices, these two or more devices may be located in a single device or in two or more separate devices. [Effects of the Invention]

[0009] According to the embodiments of this disclosure, when the sub-gear is switched, the main gear is automatically switched to a desired gear preset by the user, thereby simplifying the gear shifting operation. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a block diagram showing the schematic configuration of a work vehicle. [Figure 2] Figure 2 is a flowchart showing an example of a control method. [Figure 3] Figure 3 shows an example of the settings screen. [Figure 4] Figure 4 shows an example of conventional gear shift control. [Figure 5] Figure 5 shows another example of conventional gear shift control. [Figure 6] Figure 6 shows yet another example of conventional gear shift control. [Figure 7] Figure 7 shows an example of gear shift control in an embodiment of the present disclosure. [Figure 8] Figure 8 shows another example of gear shift control in an embodiment of the present disclosure. [Figure 9] Figure 9 is a perspective view showing an example of a work vehicle 100. [Figure 10] Figure 10 is a schematic side view showing examples of work vehicles and work machines. [Figure 11] Figure 11 is a schematic front view showing an example of a meter panel unit installed on a work vehicle. [Figure 12] Figure 12 is a front view showing an example of the arrangement of the main components of a meter panel unit. [Figure 13] Figure 13 shows an example of a meter panel unit and input device. [Figure 14] Figure 14 shows an example of a group of control switches installed inside the cabin. [Figure 15A] Figure 15A is a perspective view showing the configuration of the shift lever. [Figure 15B]FIG. 15B is a view of the shift lever as seen from a different side than FIG. 15A. [Figure 15C] FIG. 15C is a diagram for explaining the sub-shift stages that are switched by operating the shift lever. [Figure 16] FIG. 16 is a block diagram showing components related to shift control in a work vehicle. [Figure 17] FIG. 17 is a diagram showing a more specific configuration example of the transmission.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present disclosure will be described. However, detailed descriptions may be omitted more than necessary. For example, detailed descriptions of well-known matters and duplicate descriptions regarding substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art. The inventor provides the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims thereby. In the following description, components having the same or similar functions are denoted by the same reference numerals.

[0012] The following embodiments are examples, and the technology of the present disclosure is not limited to the following embodiments. For example, the numerical values, shapes, steps, the order of those steps, the layout of the display screen, etc. shown in the following embodiments are merely examples, and various modifications are possible as long as there is no technical contradiction. Also, as long as there is no technical contradiction, it is possible to combine one aspect with another aspect.

[0013] <Basic Configuration and Operation of the Embodiment> Before describing the specific embodiments of the present disclosure, the basic configuration and operation of the embodiments of the present disclosure will be described.

[0014] Figure 1 is a block diagram showing the schematic configuration of a work vehicle 100 according to an exemplary embodiment of the present disclosure. The work vehicle 100 in this embodiment includes a transmission 103 that performs gear changes by switching between a plurality of main gears and a plurality of sub-gears. The work vehicle 100 further includes an input unit 122 for the user to set the value of the main gear corresponding to at least one of the sub-gears, a storage unit 126 that stores the correspondence between the values ​​of the sub-gears and the main gears, and a control unit 120 that controls the transmission 103. When a sub-gear is switched, the control unit 120 sets the main gear to the value corresponding to the switched sub-gear based on the correspondence stored in the storage unit 126. As shown in Figure 1, the work vehicle 100 may also include a display unit 124. The display unit 124 displays, for example, a setting screen for the user to set the value of the main gear corresponding to each sub-gear.

[0015] The transmission 103 may include a main transmission 11 and a sub-transmission 12. Each of the main transmission 11 and the sub-transmission 12 is configured to allow for multiple gear changes. For example, the main transmission 11 may be configured to allow for 4, 6, 8, 10, or more gear changes. The sub-transmission 12 may be configured to allow for 2 (low, high), 3 (low, medium, high), 4 (creep, low, medium, high, etc.), or more gear changes. The gears that can be changed by the main transmission 11 are referred to as "main gears," and the gears that can be changed by the sub-transmission 12 are referred to as "sub-gears." The total number of gears in the main gears and sub-gears can be designed arbitrarily. The total number of gears in the main gears may be, for example, 4 or more and 12 or less. The total number of gears in the sub-gears may be, for example, 2 or more and 6 or less.

[0016] The input unit 122 is an input device used by the user to set the corresponding main gear value for each or some of the sub-gear stages. The display unit 124 is a display device that shows a setting screen for the user to set the corresponding main gear value for each or some of the sub-gear stages. The input unit 122 and the display unit 124 may be separate devices or may be implemented by a single device. For example, a meter panel unit including an input device, or an operating terminal such as a tablet or smartphone with a touchscreen, may function as both the input unit 122 and the display unit 124.

[0017] The control unit 120 is a control device that controls the operation of the work vehicle 100. The control unit 120 may be implemented by a computer including a processor, such as an electronic control unit (ECU) installed in the work vehicle 100. The control unit 120 may be implemented by one ECU or by multiple ECUs. Based on information input by the user via the input unit 122, the control unit 120 determines the correspondence between the sub-gear stages and the main gear stages and stores this correspondence in the storage unit 126.

[0018] The storage unit 126 is a storage device that includes any storage medium, such as a semiconductor storage medium, a magnetic storage medium, or an optical storage medium. The storage unit 126 may be a collection of multiple storage devices. The storage unit 126 may be a device independent of the control unit 120, or it may be included in the control unit 120. For example, if the ECU functions as the control unit 120, the memory in the ECU may function as the storage unit 126. The storage unit 126 may be configured to store computer programs executed by the control unit 120 and various types of information generated by the control unit 120.

[0019] Figure 2 is a flowchart showing an example of a control method performed by the control unit 120. The control unit 120 performs the operations shown in Figure 2 by executing a program stored in the memory unit 126.

[0020] In step S100, the control unit 120 determines whether or not a setting operation for the gear shift function has been performed. The setting operation is performed by the user using the input unit 122, for example, based on the setting screen displayed on the display unit 124. The setting screen is for setting the value of the corresponding main gear for each sub-gear gear. If the user performs the setting operation, the process proceeds to step S101. If the user does not perform the setting operation, the process proceeds to step S103.

[0021] Figure 3 shows an example of a settings screen displayed on the display unit 124. In this example, the sub-transmission has three settings: low (L), medium (M), and high (H), and the main transmission has eight settings: 1 to 8. In this example, the display unit 124 is a display on the meter panel located in the driver's seat, and it also displays information such as vehicle speed. The settings screen shown in Figure 3 includes areas 132, 134, and 136 for setting the main transmission values ​​corresponding to each of the three sub-transmission settings: L, M, and H. In the illustrated example, it is also possible not to set the main transmission values ​​corresponding to each sub-transmission setting, in which case the user specifies "OFF". For sub-transmission settings that are specified as "OFF", a pre-determined main transmission value (for example, 1, or the value of the main transmission setting used immediately before) is associated with them. As an example, Figure 3 shows an example where "OFF" is specified for the L setting of the sub-transmission, "3" is specified for the M setting of the sub-transmission, and "6" is specified for the H setting of the sub-transmission. The user can apply the settings by changing the values ​​in areas 132, 134, and 136 using the input unit 122. In this way, the display unit 124 may display whether or not to set the corresponding main gear value for each sub-gear gear.

[0022] In the example shown in Figure 3, a graphical user interface (GUI) is displayed as the settings screen, visually showing the main gear settings for each sub-gear. This GUI allows the user to easily set the main gear values ​​corresponding to each sub-gear.

[0023] Once the setup operation is complete, the process proceeds to step S101. In step S101, the control unit 120 sets the value of the main gear corresponding to each sub-gear gear specified by the user. In the following step S102, the control unit 120 stores the correspondence between the set values ​​of the sub-gear gears and the main gear in the storage unit 126. For example, for each of the sub-gear gears L, M, and H, the control unit 120 stores in the storage unit 126 the value of the corresponding main gear, or data such as a table indicating that the value of the corresponding main gear is not set (the aforementioned "OFF"). Thereafter, when a sub-gear gear is switched, the control unit 120 automatically sets the main gear based on the correspondence stored in the storage unit 126.

[0024] In step S103, the control unit 120 determines whether or not the sub-gear has been switched. The control unit 120 can determine whether or not the sub-gear has been switched based, for example, on a signal from a sensor attached to the lever for switching the sub-gear. If the sub-gear has been switched, the process proceeds to step S104. If the sub-gear has not been switched, the process returns to step S100.

[0025] In step S104, the control unit 120 sets the main gear to a value corresponding to the sub-gear gear after switching, based on the correspondence stored in step S102. For example, as shown in Figure 3, if the value of the main gear gear associated with the M gear of the sub-gear is "3", and the sub-gear gear is switched from the L gear or H gear to the M gear, the control unit 120 sets the main gear to "3". If the main gear gear immediately before switching the sub-gear gear is different from "3", the main gear gear is switched to "3", and if the main gear gear immediately before switching the sub-gear gear is "3", the main gear gear is maintained at "3".

[0026] With this control system, when the user switches to a sub-gear, the main gear is automatically set according to the correspondence between the sub-gear and main gear that the user has pre-set. Therefore, for users who frequently set a specific main gear when using a specific sub-gear, for example, this reduces the effort required to switch the main gear and improves convenience.

[0027] In this embodiment, the correspondence between the sub-gear gear and the main gear values, once stored, is not erased even when the work vehicle 100 stops (e.g., engine off). Therefore, even if the sub-gear gear is switched to a specific gear while the work vehicle 100 is not moving after starting (e.g., engine on), if the main gear value corresponding to that sub-gear gear has been previously set, that main gear will be automatically set. In other words, if the main gear value corresponding to the sub-gear gear is set before the work vehicle 100 stops, and the sub-gear gear is switched after the work vehicle 100 starts, the control unit 120 sets the main gear to the value set before the work vehicle 100 stopped, which corresponds to the sub-gear gear after the switch. This allows the combination of the sub-gear gear and the main gear to be appropriately set according to the user's preference, even immediately after the work vehicle 100 starts.

[0028] Here, the effects of this embodiment will be explained in more detail in comparison with the conventional technology.

[0029] Figure 4 shows an example of conventional gear shift control. Figure 4 shows examples of changes in the combination of the shuttle lever, sub-gear, and main gear. Here, the shuttle lever is a lever for switching the forward and reverse of the work vehicle, and takes three states: forward (F), neutral (N), and reverse (R). The sub-gear is switched, for example, by the shift lever, and takes four states: N (neutral), L (low), M (medium), and H (high). The main gear is switched, for example, by the shift up and shift down buttons provided on the shift lever, and is set to one of eight values ​​from 1 to 8.

[0030] In the example shown in Figure 4, after the work vehicle is started (for example, after the engine starts), the main transmission is set to "1" as shown in Figure 4 (1). At startup, the shuttle lever and auxiliary transmission are in the "N" position. If the user shifts up or down in this state, the value of the main transmission increases or decreases. For example, Figure 4 (2) shows the state where the main transmission has increased to "2" due to shifting up. Even if the user switches the auxiliary transmission from "N" to "L" in this state, the main transmission remains at "2" as it was before the switch, as shown in Figure 4 (3). Even if the auxiliary transmission is switched to "M" or "H", the value of the main transmission does not change unless the user voluntarily shifts up or down (Figures 4 (4) and (5)).

[0031] As shown in Figure 4, when the sub-gear is switched, the value of the main gear is not automatically changed. Therefore, if the value of the main gear after switching the sub-gear is different from the value desired by the user, the user needs to perform an operation to change the value of the main gear.

[0032] Figure 5 shows another example of conventional gear shift control. In this example, while the work vehicle is in operation, the combination of the sub-gear and main gear values ​​is stored in memory, and when the sub-gear gear is switched, it is automatically set to the stored main gear value. For example, consider the case where the work vehicle is running with the sub-gear set to "M" and the main gear set to "3", as shown in Figure 5(1). The combination of the sub-gear and main gear values ​​at this time is stored in memory. In this state, suppose the user switches the sub-gear from "M" to "L" and performs an upshift or downshift operation to the state shown in Figure 5(2). The work vehicle is running in this state, and when the user switches the sub-gear from "L" to "M", the main gear is automatically switched to the previously stored value "3", as shown in Figure 5(3).

[0033] As shown in the example in Figure 5, when the sub-transmission is switched, if a previously set main transmission value is stored, the main transmission is automatically set to that value. This function is referred to as "memory transmission" in this specification. The memory is volatile memory, and the stored values ​​are erased when the work vehicle 100 is stopped (i.e., when the engine is turned off or the power is turned off).

[0034] In the example in Figure 5, memory shifting occurs when the sub-transmission is switched from "L" to "M," but memory shifting can also occur when switching from "M" to "L," from "M" to "H," and from "H" to "M." However, when the sub-transmission is switched from "M" to "H," if the main gear used immediately before the corresponding "H" is, for example, 4 or higher, control may be implemented to limit the main gear to, for example, 3 or lower to prevent sudden acceleration.

[0035] Figure 6 shows yet another example of conventional gear shift control. In this example, when the auxiliary gear is switched, the main gear is automatically set to the gear whose reduction ratio is closest to the reduction ratio before the switch. "Reduction ratio" is the ratio of the engine speed after the gear shift to the engine speed. "Engine speed" means the number of revolutions per unit time (e.g., 1 minute). For example, as shown in (1) of Figure 6, the work vehicle is running with the auxiliary gear set to "M" and the main gear set to "1", and as shown in (2), after the work vehicle starts, the auxiliary gear is switched to "L", which is not yet running. In this case, the main gear is switched to "8", which is the value closest to the previous reduction ratio. As another example, when the auxiliary gear is switched to "H" from a state where the auxiliary gear is set to "M" and the main gear is set to "5", the main gear is switched to "1", which is the value closest to the previous reduction ratio. This type of control makes the change in the reduction ratio after switching the auxiliary gear small, and makes starting smoother. This function is referred to as "near-shift" in this specification. Near-shift may be used in conjunction with memory shift, as shown in Figure 5. For example, after starting the engine, if the vehicle can be switched to a sub-transmission gear that has been driven before, memory shift may be performed, and if it can be switched to a sub-transmission gear that has not been driven before, near-shift may be performed.

[0036] In the gear shift control shown in Figures 4 to 6, when the sub-gear is switched, the main gear is set to a predetermined value determined by the system, or a value stored from when that sub-gear was used in the past, rather than a value desired by the user. Therefore, in order to change the combination of the sub-gear and main gear to the user's desired combination, it is necessary to shift up or down the main gear. For example, for a user who always wants the main gear to be "5" when the sub-gear is "H", if the main gear is automatically set to a value such as "1" when the sub-gear is switched, it may be troublesome as it requires shifting up or down. Also, if the user wants to set the main gear to a value other than "1" when the engine has started but the vehicle is not yet in motion, it is necessary to shift up.

[0037] According to this embodiment, the user can set a desired main gear value for each sub-gear. As a result, when the sub-gear is switched, it is automatically set to the user's desired main gear, reducing the number of operations required to switch the main gear and improving convenience.

[0038] Figure 7 shows an example of gear shift control in this embodiment. In this example, as shown in Figure 7(a), the user has set the main gear value corresponding to the sub-gear "L" to "2", the main gear value corresponding to the sub-gear "M" to "3", and the main gear value corresponding to the sub-gear "H" to "4". In this case, as shown in Figure 7(1), when the sub-gear is set to "L" and the main gear is set to "1", and the sub-gear is switched to "M", the main gear is switched to "3", as shown in Figure 7(2). Furthermore, when the sub-gear is switched to "H", the main gear is switched to "4", as shown in Figure 7(3). Finally, when the sub-gear is switched to "L", the main gear is switched to "2", as shown in Figure 7(4).

[0039] Figure 8 shows another example of gear shift control in this embodiment. In this example, as shown in Figure 8(a), the main gear value corresponding to the sub-gear "L" is set to "5", the main gear value corresponding to the sub-gear "M" is not set ("OFF"), and the user has set the main gear value corresponding to the sub-gear "H" to "2". In this case, as shown in Figure 8(1), the work vehicle is running with the sub-gear set to "L" and the main gear set to "3", and when the sub-gear is switched to "M", either a near gear shift or a memory gear shift operation is performed as shown in Figure 8(2) or (2'). If the vehicle has not been driven with the sub-gear set to "M" since the engine started, a near gear shift is performed. In a near gear shift, the main gear is set to achieve the reduction ratio closest to the previous reduction ratio (in the example of Figure 8(2), it is "1"). If the vehicle has been driven with the sub-gear set to "M" since the engine started, a memory gear shift is performed. In memory shifting, the value of the main gear used during the previous M gear shift (indicated as "x" in Figure 8 (2')) is read from memory, and the main gear is set to that value. If the sub-gear is switched to "H", the main gear is switched to "2", as shown in Figure 8 (3). Furthermore, if the sub-gear is switched to "L", the main gear is switched to "5", as shown in Figure 8 (4).

[0040] Thus, in this embodiment, the user can set the value of the main gear for each of the sub-gears. When a sub-gear is switched, the main gear is set to the value corresponding to the switched sub-gear. This gear control is also applied when the work vehicle is driven for the first time in the switched sub-gear after the engine has started (i.e., after the work vehicle has started). For this reason, the main gear setting for each sub-gear is stored in a non-volatile memory device.

[0041] When the setting of the main gear corresponding to the sub-gear gear is "OFF", the same gear shift control as shown in Figures 4 to 6 may be performed for that sub-gear gear. For example, if the work vehicle 100 has already been running with a sub-gear gear set to "OFF" after starting up, and then runs with a different sub-gear gear before switching back to a sub-gear gear set to "OFF", the main gear will be set to the value of the main gear gear used during the previous run (memory shift). To realize this memory shift function, the storage unit 126 stores the changed combination when the combination of sub-gear gear and main gear is changed. When the sub-gear gear is switched to a gear for which no corresponding main gear value is set, the control unit 120 switches the main gear to the value of the main gear gear stored when the work vehicle 100 last ran with that sub-gear gear.

[0042] Furthermore, if the work vehicle 100 has not traveled at all in the sub-gear set to "OFF" since starting up, and then travels in a different sub-gear before switching to the sub-gear set to "OFF", the main gear is set to a value that achieves the reduction ratio closest to the reduction ratio before the switch (i.e., the value that minimizes the change in the reduction ratio before and after the switch) (near shift). In other words, if the sub-gear is switched to a sub-gear that has not been used since the work vehicle 100 started up, and the value of the main gear corresponding to that sub-gear is not set, the control unit 120 switches the main gear to a main gear that achieves the reduction ratio closest to the reduction ratio before the sub-gear was switched.

[0043] As a result of the above operation, in addition to allowing the user to freely set the main gear for each sub-gear, conventional gear shifting control methods such as memory shifting or near shifting can also be applied according to the user's preference. This enables appropriate gear shifting control that meets the user's needs.

[0044] The following describes an embodiment in which the technology of this disclosure is applied to an agricultural tractor, which is an example of a work vehicle. The technology of this disclosure is not limited to tractors and can be applied to any work vehicle. The work vehicle may be, for example, a rice transplanter, combine harvester, lawnmower, harvester, snowplow, or construction vehicle.

[0045] <Example of work vehicle configuration> Figure 9 is a perspective view showing an example of a work vehicle 100 in an exemplary embodiment of the present disclosure. Figure 10 is a schematic side view showing an example of a work vehicle 100 and an implement 300 connected to the work vehicle 100. In this embodiment, the work vehicle 100 is a tractor used for agricultural work in fields (e.g., fields, orchards, paddy fields, etc.).

[0046] The work vehicle 100 shown in Figure 10 comprises a vehicle body 101, a prime mover (engine) 102, a transmission 103, and a running gear 104. The vehicle body 101 is provided with a cabin 105. The running gear 104 includes four wheels with tires (front wheels 104F and rear wheels 104R), an axle that rotates the four wheels, and a braking device (brake) that brakes each wheel. One or both of the front wheels 104F and rear wheels 104R may be replaced with multiple wheels fitted with tracks (crawlers) instead of wheels with tires.

[0047] Inside the cabin 105 are a driver's seat 107, a steering gear 106, several pedals 109, an instrument panel unit 110, and a group of switches (operators) for operation.

[0048] The prime mover 102 may be, for example, a diesel engine. An electric motor may be used instead of a diesel engine. The transmission 103 can change the propulsion force and travel speed of the work vehicle 100 by shifting gears. The transmission 103 can also switch the work vehicle 100 between forward and reverse.

[0049] The steering system 106 includes a steering wheel, a steering shaft connected to the steering wheel, and a power steering system that assists steering by the steering wheel. The front wheels 104F are steering wheels, and by changing their steering angle, the direction of travel of the work vehicle 100 can be changed. The steering angle of the front wheels 104F can be changed by operating the steering wheel. The power steering system includes a hydraulic system or electric motor that supplies auxiliary force to change the steering angle of the front wheels 104F. The work vehicle 100 may also have an automatic steering function. When automatic steering is performed, the steering angle of the front wheels 104F is automatically adjusted by the force of the hydraulic system or electric motor under control from a control device located inside the work vehicle 100.

[0050] The multiple pedals 109 include an accelerator pedal, a clutch pedal, and a brake pedal. Each pedal is equipped with a sensor to detect when it is pressed.

[0051] A coupling device 108 is provided at the rear of the vehicle body 101. The coupling device 108 may include, for example, a three-point support device (also called a "three-point link" or "three-point hitch"), a PTO (Power Take Off) shaft, a universal joint, and a communication cable. The coupling device 108 allows the work implement 300 to be attached to and detached from the work vehicle 100. The coupling device 108 can change the position or orientation of the work implement 300 by raising and lowering the three-point link, for example, by a hydraulic system. Power can also be supplied from the work vehicle 100 to the work implement 300 via the universal joint. The work vehicle 100 can pull the work implement 300 and cause the work implement 300 to perform a predetermined operation. The coupling device may be provided at the front of the vehicle body 101. In that case, the work implement can be connected to the front of the work vehicle 100.

[0052] The implement 300 shown in Figure 10 is a rotary tiller, but the implement 300 is not limited to a rotary tiller. For example, any implement such as a mower, seeder, spreader, rake, baler, harvester, sprayer, or harrow can be attached to the work vehicle 100 and used. The work vehicle 100 may also be driven without the implement 300 attached.

[0053] <Outline configuration of the meter panel unit> Figure 11 is a schematic front view showing an example of a meter panel unit 110 mounted on a work vehicle 100. The meter panel unit 110 is an example of a display device (or display unit) provided by the work vehicle 100. The meter panel unit 110 is configured to display the operating status of the work vehicle 100 and to display a setting screen for the user to make various settings related to the work vehicle 100. The meter panel unit 110 displays a setting screen for making settings related to the main and sub-transmissions of the work vehicle 100, for example, as shown in Figure 3. In the example shown in Figure 11, the meter panel unit 110 is located on the front side of the driver's seat of the work vehicle 100. Specifically, the meter panel unit 110 is fitted into an opening in the meter cover 240 above the handle stay 230 that rotatably supports the steering wheel (handle) 220. The meter panel unit 110 is provided in a position visible to the driver seated in the driver's seat.

[0054] Figure 12 is a front view showing an example of the arrangement of the main components of the meter panel unit 110. The meter panel unit 110 shown in Figure 12 includes a first analog meter 111, a second analog meter 112, and a display 113. The display 113 is located between the first analog meter 111 and the second analog meter 112.

[0055] The first analog meter 111 has an indicator needle 114A. The second analog meter 112 has indicator needles 114B and 114C. Indicator needle 114A indicates, for example, engine speed, i.e., the number of engine revolutions per unit time (e.g., 1 minute), depending on the direction its tip points. Indicator needle 114B indicates, for example, the remaining fuel level, depending on the direction its tip points. Indicator needle 114C indicates, for example, the engine coolant temperature (water temperature), depending on the direction its tip points.

[0056] The display 113 shown in Figure 12 is, for example, an active-matrix display such as a liquid crystal display panel or an OLED (Organic Light Emitting Diode). The display 113 has a large number of pixels arranged two-dimensionally in the display area, and a display visible to the human eye is realized by the light emitted from the large number of pixels. In the display 113 in this embodiment, each pixel includes RGB subpixels, and a color image can be displayed. Unlike an analog meter, the display 113 can display numbers, characters, figures, icons, symbols, still images, or moving images of any size at any position within the display area. In this embodiment, the display 113 functions as the display unit 124 shown in Figure 1.

[0057] Figure 13 shows an example of a meter panel unit 110 and an input device 170 connected to the meter panel unit 110. The user can use the input device 170 to change the display of content on the display area and select various setting items. In this embodiment, the input device 170 functions as the input unit 122 shown in Figure 1.

[0058] In the example shown in Figure 13, an input device 170 enabling user-interactive operation is connected to the meter panel unit 110 via a communication cable. The input device 170 includes a selector switch 171, such as a jog dial, and an operation switch 172. The input device 170 may be connected to the meter panel unit 110 wirelessly or via a wired connection. Alternatively, the input device 170 may be connected to a control device of the work vehicle 100 and send input signals to the meter panel unit 110 via CAN (Controller Area Network) communication. Any device that accepts user input can be used as the input device 170. The input device 170 may be, for example, a rotary switch, a slide switch, a push-button switch, a touchscreen, a joystick, or a combination of two or more of these.

[0059] Display 113 may display various images indicating information about the work vehicle. This information includes, for example, information related to the internal combustion engine, vehicle body, PTO shaft, hydraulic / three-point hitch, and electrical components of the vehicle body. This information indicates the internal state of the vehicle system. Information related to the vehicle body includes, for example, information regarding the vehicle's direction of travel, clutch, gear shift, brakes, headland control, and cruise control. Display 113 also displays setting screens, as shown in Figure 3. Furthermore, Display 113 may also display various other content, such as camera images, radio setting screens, and audio setting screens.

[0060] <Example of a group of control switches> Figure 14 shows an example of a group of operating switches located inside the cabin 105. Inside the cabin 105 is a group of switches 210, which includes multiple switches (including buttons, levers, and pedals) that can be operated by the user. The group of operating switches 210 may include switches for switching the main gear (e.g., buttons), switches for switching the sub-gear (e.g., shift levers), and switches for switching between forward and reverse (e.g., shuttle levers). Pedals such as the clutch pedal, accelerator pedal, and brake pedal are also included in the group of switches 210. The input device 170 shown in Figure 13 may also be included in the group of switches 210.

[0061] Figures 15A to 15C illustrate the configuration of the shift lever 211 included in the operating switch group 210. The shift lever 211 is used by the user to switch between the main and sub-gears. Figure 15A is a perspective view showing the configuration of the shift lever 211. Figure 15B is a view of the shift lever 211 from a different side than in Figure 15A. Figure 15C is a diagram illustrating the sub-gears that can be switched by operating the shift lever 211. The shift lever 211 shown in these figures includes a clutch button 212, a shift-up button 213, and a shift-down button 214. The user can switch the sub-gears by moving the shift lever 211. When switching the sub-gears, the user must either press the clutch button 212, depress the clutch pedal, or set the shuttle lever for forward / reverse to neutral. By pressing the shift-up button 213, the user can shift up one gear in the main gear, and by pressing the shift-down button 214, the user can shift down one gear in the main gear.

[0062] In this embodiment, as shown in Figure 15C, the auxiliary transmission has three gears: low speed (L), medium speed (M), and high speed (H). When switching between L and M, or between M and H, the user first moves the shift lever 211 to the neutral (N) position before making the switch. Note that the total number of gears in the auxiliary transmission is not limited to 3; it may be 2 or 4 or more. The total number of gears in the auxiliary transmission is typically between 2 and 6, but is not limited to this range.

[0063] The total number of gears in the main transmission is, for example, 8. In this case, the user can switch from the slowest 1st gear to the fastest 8th gear by pressing the shift-up button 213 or the shift-down button 214. The total number of gears in the main transmission is not limited to 8; it may be 7 or less, or 9 or more. The total number of gears in the main transmission is typically between 4 and 12, but is not limited to this range.

[0064] <Example configuration for gear shift control> Figure 16 is a block diagram showing the components related to gear shift control in the work vehicle 100. The work vehicle 100 shown in Figure 16 includes an operation switch group 210, a control device 150, a storage device 160, a gear shift device 103, a meter panel unit 110, and an input device 170.

[0065] The control switch group 210 includes a plurality of operating devices used by the user to operate the work vehicle 100. The operating devices include, for example, a shift lever 211, a clutch button 212, a shift-up button 213, a shift-down button 214, a shuttle lever 216, a clutch pedal 217, and an input device 170. The input device 170 may be connected to the meter panel unit 110.

[0066] The control device 150 is an on-board computer that controls the operation of the work vehicle 100. The control device 150 can be implemented by one or more electronic control units (ECUs). The control device 150 may include, for example, an ECU that controls the transmission 103 and an ECU that controls the instrument panel unit 110. Each ECU comprises one or more processors and one or more memories. When the control device 150 is implemented by multiple ECUs, these ECUs can communicate with each other according to a vehicle bus standard such as CAN. The control device 150 functions as the control unit 120 shown in Figure 1.

[0067] The storage device 160 includes one or more storage media, such as flash memory or magnetic disks. The storage device 160 stores various data generated by the control device 150. The storage device 160 also stores computer programs that cause the control device 150 to perform various operations, which will be described later. Such computer programs can be provided to the work vehicle 100 via a storage medium (e.g., semiconductor memory or optical disk) or a telecommunications line (e.g., the Internet). Such computer programs may be sold as commercial software. The memory included in the control device 150 may also function as the storage device 160. The storage device 160 functions as the storage unit 126 shown in Figure 1.

[0068] The transmission 103 includes a forward / reverse selector 10, a main transmission 11, and a sub-transmission 12. The forward / reverse selector 10 switches the power from the prime mover 102 between power for forward travel and power for reverse travel. The main transmission 11 switches the power from the forward / reverse selector 10 to multiple gears (e.g., 8 gears). The sub-transmission 12 switches the power from the main transmission 11 to multiple gears (e.g., 3 gears). An example of the configuration of the transmission 103 will be described in more detail below with reference to Figure 17.

[0069] Figure 17 shows a more specific example of the configuration of the transmission 103. The transmission 103 shown in Figure 17 includes a forward / reverse selector 10, a main transmission 11, and a sub-transmission 12, as well as a PTO power transmission 13 and a front wheel power transmission 14.

[0070] The forward / reverse switching device 10 switches the power transmitted from the crankshaft 15 of the prime mover 102 to the drive shaft 16 of the drive system. That is, the forward / reverse switching device 10 switches the direction of rotation of the drive shaft 16 to either forward (forward) or reverse (reverse). The forward / reverse switching device 10 includes a transmission shaft 20, a hydraulic clutch 21, and a number of gears 22, 23, 24, and 25. The transmission shaft 20 rotates in conjunction with the rotation of the crankshaft 15. The hydraulic clutch 21 is switched between forward and reverse by hydraulic pressure. When the hydraulic clutch 21 is switched to the forward position, the power of the transmission shaft 20 is transmitted to the drive shaft 16 via gears 25 and 26. When the hydraulic clutch 21 is switched to the reverse position, the power of the transmission shaft 20 is transmitted to the drive shaft 16 via gears 22, 23, 24, 25, and 26.

[0071] The main transmission 11 includes a first main switching section 31, a second main switching section 32, a third main switching section 33, and a plurality of gears 34 to 44. The plurality of gears 34 to 44 are of different sizes, so that the power transmitted via the drive shaft 16 can be switched between multiple stages. The main transmission 11 switches between four stages using gears 34 to 41, and between two stages using gears 39, 42 to 44. In other words, the main transmission 11 is capable of eight speeds.

[0072] The first main switching unit 31, the second main switching unit 32, and the third main switching unit 33 are each hydraulic clutches that can be switched between one side and the other side. When the first main switching unit 31 is switched to one side, the power of the drive shaft 16 is transmitted via gears 34 and 41 to gear 43 which meshes with gear 42 and gear 44 which meshes with gear 39. When the first main switching unit 31 is switched to the other side, the power of the drive shaft 16 is transmitted to gear 43 via gears 35, 40, and 42, and then to gear 44 via gears 35, 40, and 39.

[0073] When the second main switching unit 32 is switched to one side, the power of the drive shaft 16 is transmitted to gear 44 via gears 36 and 39, and then to gear 43 via gears 36, 39, and 42. When the second main switching unit 32 is switched to the other side, the power of the drive shaft 16 is transmitted to gear 43 via gears 37, 38, and 42, and then to gear 44 via gears 37, 38, and 39.

[0074] When the third main switching unit 33 is switched to one side, the power transmitted to the gear 43 is transmitted to the transmission shaft 47. When the third main switching unit 33 is switched to the other side, the power transmitted to the gear 44 is transmitted to the transmission shaft 47.

[0075] The sub-transmission 12 includes a creep section 50, a first sub-switching section 51, and a second sub-switching section 52. The creep section 50 is connected to the transmission shaft 47 and is switched between one side and the other by a shifter. When the creep section 50 is switched to one side, the power of the transmission shaft 47 is transmitted to the transmission shaft 57 via the shifter. When the creep section 50 is switched to the other side, the power of the transmission shaft 47 is transmitted to the transmission shaft 57 via gears 53 to 56. In other words, when the creep section 50 is switched to one side, the power of the transmission shaft 47 is transmitted to the transmission shaft 57 without reduction, and when the creep section 50 is switched to the other side, the power of the transmission shaft 47 is reduced by gears 53 to 56 and transmitted to the transmission shaft 57.

[0076] The first sub-switching unit 51 includes a shifter 61 and a gear 62. The shifter 61 can rotate with the transmission shaft 57 and move in the axial direction. The gear 62 can rotate relative to the transmission shaft 57. The position of the shifter 61 is controlled by the control device 150 and switched between a neutral position and a high-speed position. When the shifter 61 is switched to the high-speed position and engages with the rotating body 67, the power from the transmission shaft 57 is transmitted to the output shaft 66 via gears 62, 63, 64, and 65. Here, gears 63 and 64 are configured to rotate with the transmission shaft 80, and gear 65 is configured to rotate with the output shaft 66.

[0077] The second sub-switching unit 52 includes gears 71, 72, 74, 76, and 77, rotating bodies 73 and 78, a transmission body 75, and a shifter 79. Gear 71 is configured to rotate with the transmission shaft 57. Gear 72 meshes with gear 71. Rotating body 73 rotates with gear 72. Gear 74 rotates with rotating body 73. Transmission body 75 rotates relative to the transmission shaft 57 and rotates in conjunction with the rotation of gear 74. Gear 76 rotates with transmission body 75. Gear 77 meshes with gear 76. Rotating body 78 rotates in conjunction with the rotation of gear 77. The shifter 79 rotates with the transmission shaft 80 and can move in the axial direction. The position of the shifter 79 is controlled by the control device 150 and can be switched between a low-speed position, a neutral position, and a medium-speed position.

[0078] When the shifter 79 is switched from the neutral position to the low-speed position and the shifter 79 engages with the rotating body 73, the power of the transmission shaft 57 is transmitted to the transmission shaft 80 via gears 71, 72 and the shifter 79. When the shifter 79 is switched from the neutral position to the medium-speed position and the shifter 79 engages with the rotating body 78, the power of the transmission shaft 57 is transmitted to the transmission shaft 80 via gears 71, 72, the rotating body 73, gear 74, transmission body 75, gears 76, 77, the rotating body 78, and the shifter 79.

[0079] With this configuration, the auxiliary transmission 12 can be switched between three speeds: high speed (H), medium speed (M), and low speed (L). When the auxiliary transmission 12 is switched to the high speed (H) speed, the control device 150 switches the shifter 61 to the high speed position and the shifter 79 to the neutral position. When the auxiliary transmission 12 is switched to the medium speed (M) speed, the control device 150 switches the shifter 61 to the neutral position and the shifter 79 to the medium speed position. When the auxiliary transmission 12 is switched to the low speed (L) speed, the control device 150 switches the shifter 61 to the neutral position and the shifter 79 to the low speed position. The movement of the shifters 61 and 79 is performed using a hydraulic system that includes multiple electromagnetic valves. The switched power is transmitted to the rear wheel differential 82, which rotates the rear wheels, via the output shaft 66.

[0080] The PTO power transmission device 13 includes a PTO rotating shaft 27 to which power from the transmission shaft 20 is transmitted, and a switching mechanism 28 for switching the power of the PTO rotating shaft 27. Power from the prime mover 102 is transmitted to the PTO shaft 29 via the PTO rotating shaft 27 and the switching mechanism 28 by the PTO power transmission device 13.

[0081] The front wheel power transmission device 14 includes a transmission shaft 18 through which power from the output shaft 66 is transmitted via gears, and a switching mechanism 19. The power switched by the switching mechanism 19 is transmitted to the front wheel 104F.

[0082] <Operation of gear shift control> In this embodiment, the control device 150 displays a setting screen, for example, as shown in Figure 3, on the display 113 of the meter panel unit 110. The user uses the input device 170 to set the value of the main transmission gear corresponding to each sub-transmission gear on the setting screen. Based on this operation, the control device 150 generates information (e.g., a table) showing the correspondence between the sub-transmission gear and main transmission gear values ​​and stores it in the storage device 160. This operation can be performed, for example, when the work vehicle 100 is not moving. The storage device 160 is a non-volatile storage device, and the stored information is not erased even after the work vehicle 100 is stopped (i.e., after the engine is turned off or the power is turned off).

[0083] Subsequently, when the user operates the shift lever 211 to switch the sub-gear, the control device 150 sets the main gear to the value corresponding to the switched sub-gear based on the stored correspondence. In this way, when the sub-gear is switched by user operation using an operating tool, the control device 150 sets the main gear to the value corresponding to the switched sub-gear. The control device 150 can detect, for example, that the sub-gear has been switched from one gear to another based on a signal from a sensor provided on the shift lever 211. More specifically, the control device 150 controls the transmission 103 in the manner described with reference to Figures 2, 7, and 8. By applying such control, the user's gear shifting operation can be simplified and convenience can be greatly improved.

[0084] In this embodiment, it is assumed that the user (driver) operates the work vehicle 100, but the work vehicle 100 may be equipped with an automatic driving or automatic transmission control function. Even when automatic driving or automatic transmission control is performed, the main transmission gear may be automatically set when switching between sub-transmission gears based on the main transmission gear values ​​for each sub-transmission gear set in advance by the user.

[0085] The control system, including the control unit and memory unit in the above embodiment, can also be retrofitted to a work vehicle. Such a system can be manufactured and sold independently of the work vehicle. Computer programs used in such systems can also be manufactured and sold independently of the work vehicle. Computer programs can be provided, for example, stored in a computer-readable non-temporary storage medium. Computer programs can also be provided by download via a telecommunications line (e.g., the Internet).

[0086] As described above, this disclosure includes the work vehicle, control method, and program described in the following items.

[0087] [Item 1] A transmission that changes gears by switching between multiple main gears and multiple sub-gears, An input unit for the user to set the value of the main gear corresponding to at least one of the plurality of sub-gear gears, A storage unit that stores the correspondence between the aforementioned sub-gear stage and the aforementioned value, When the sub-gear stage is switched, a control unit sets the main gear stage to the value corresponding to the switched sub-gear stage based on the correspondence relationship, A work vehicle equipped with the following features.

[0088] [Item 2] The control unit is configured such that the value is set before the work vehicle stops, and when the sub-gear is switched after the work vehicle starts, the main gear is set to the value set before the work vehicle stops, corresponding to the sub-gear after the switch, the work vehicle according to item 1.

[0089] [Item 3] A work vehicle according to item 1 or 2, comprising a display unit that displays a setting screen for setting the aforementioned value.

[0090] [Item 4] The work vehicle described in item 3, wherein the display unit displays whether or not to set the value for each of the sub-gear stages.

[0091] [Item 5] The storage unit stores the changed combination when the combination of the sub-gear stage and the main gear stage is changed. When the control unit switches to the sub-gear gear for which no value is set, it switches the main gear gear to the value of the main gear gear that was stored when the work vehicle last traveled in the sub-gear gear. Work vehicles as described in item 4.

[0092] [Item 6] The control unit, when the sub-gear stage is switched to a sub-gear stage that has not been used since the work vehicle was started, and the value of the main gear stage corresponding to the sub-gear stage is not set, switches the main gear stage to the main gear stage that achieves the reduction ratio closest to the reduction ratio before the sub-gear stage was switched. Work vehicles as described in item 4 or 5.

[0093] [Item 7] Equipped with a control device operated by the user, When the sub-gear gear is switched by the user's operation using the operating tool, the control unit sets the main gear to the value corresponding to the switched sub-gear gear. A work vehicle listed in any of items 1 through 6.

[0094] [Item 8] The total number of gears in the main transmission is between 4 and 12. The total number of sub-gear stages is between 2 and 6. A control system as described in any of items 1 through 7.

[0095] [Item 9] A control method for a work vehicle equipped with a transmission that performs gear changes by switching between multiple main gears and multiple sub-gears, In response to user operation using an input device, the value of the main gear corresponding to at least one of the plurality of sub-gear gears is set, The correspondence between the aforementioned sub-gear stage and the aforementioned value is stored in a memory device, When the aforementioned sub-gear stage is switched, the main gear stage is set to the value corresponding to the switched sub-gear stage based on the aforementioned correspondence relationship, A control method including

[0096] [Item 10] A program for controlling a work vehicle equipped with a transmission that performs gear changes by switching between multiple main gears and multiple sub-gears, In response to user operation using an input device, the value of the main gear corresponding to at least one of the plurality of sub-gear gears is set, The correspondence between the aforementioned sub-gear stage and the aforementioned value is stored in a memory device, When the aforementioned sub-gear stage is switched, the main gear stage is set to the value corresponding to the switched sub-gear stage based on the aforementioned correspondence relationship, A program that causes a computer to execute something. [Industrial applicability]

[0097] The technology disclosed herein can be used, for example, in agricultural vehicles such as tractors, harvesters, or transplanters. The technology disclosed herein is not limited to agricultural applications but can also be applied to vehicles used in other applications. [Explanation of symbols]

[0098] 10 Forward / Reverse Switching Device 11 Main transmission 12. Sub-transmission 13 PTO power transmission device 14 Front wheel power transmission system 100 work vehicles 101 Vehicle body 102 Engine 103 Transmission 104 Running gear 105 Cabin 106 Steering gear 107 Driver's seat 108 Coupling device 109 pedals 110 Meter Panel Unit 111 First Analog Meter 112 Second Analog Meter 113 displays 114A, 114B, 114C Indicator needle 115 Meter section 150 Control device 160 Storage device 170 Input devices 171 Selector switch 172 Operating switches 200 Operating terminals 210 Operating switch group 211 Shift lever 212 Clutch button 213 Shift Up Button 214 Shift Down Button 215 Sub-transmission indicator 216 Shuttle Lever 217 Clutch pedal 220 Steering Wheel 230 Handlebar Stay 240 Meter Cover 300 work machines

Claims

1. A transmission that changes gears by switching between multiple main gears and multiple sub-gears, A display unit that displays a graphical user interface including a setting screen for the user to set the value of the main gear corresponding to each of the plurality of sub-gear gears, A storage unit that stores the correspondence between each of the plurality of sub-gear stages and the corresponding value of the main gear stage, which is set via the graphical user interface. When the sub-gear stage is switched, a control unit sets the main gear stage to the value corresponding to the switched sub-gear stage based on the correspondence relationship, A work vehicle equipped with the following features.

2. The aforementioned storage unit is a non-volatile memory device. The control unit sets the value of the main gear corresponding to each of the plurality of sub-gear gears before the work vehicle is stopped by a power-off operation, and when the sub-gear gear is switched after the work vehicle is started by a power-on operation, the control unit sets the main gear to the value that was set before the work vehicle was powered off, corresponding to the sub-gear gear after the switch.

3. The work vehicle according to claim 1, wherein the setting screen displays a selection of whether or not to set the value for each of the sub-gear stages.

4. The storage unit stores the changed combination when the combination of the sub-gear stage and the main gear stage is changed. When the control unit switches to the sub-gear gear for which no value is set, it switches the main gear gear to the value of the main gear gear that was stored when the work vehicle last traveled in the sub-gear gear. The work vehicle according to claim 3.

5. The control unit will determine if the auxiliary gear is switched to an auxiliary gear that has not been used since the work vehicle was started, and if the value of the main gear corresponding to the auxiliary gear is not set. At that time, the main gear is switched to the main gear that achieves the reduction ratio closest to the reduction ratio before the switch of the sub-gear gear. The work vehicle according to claim 3 or 4.

6. Equipped with a control device operated by the user, When the sub-gear gear is switched by the user's operation using the operating tool, the control unit sets the main gear to the value corresponding to the switched sub-gear gear. A work vehicle according to any one of claims 1 to 4.

7. The total number of gears in the main transmission is between 4 and 12. The total number of sub-gear stages is between 2 and 6. A work vehicle according to any one of claims 1 to 4.

8. A control method for a work vehicle equipped with a transmission that performs gear changes by switching between multiple main gears and multiple sub-gears, In response to user operation using a display device that shows a graphical user interface including a setting screen for the user to set the value of the main gear corresponding to each of the plurality of sub-gear stages, the value of the main gear corresponding to each of the plurality of sub-gear stages is set. The correspondence between each of the multiple sub-gear stages and the corresponding main gear stage values, as set via the graphical user interface, is stored in a memory device. When the aforementioned sub-gear stage is switched, the main gear stage is set to the value corresponding to the switched sub-gear stage based on the aforementioned correspondence relationship, A control method including

9. A program for controlling a work vehicle equipped with a transmission that performs gear changes by switching between multiple main gears and multiple sub-gears, In response to user operation using a display device that shows a graphical user interface including a setting screen for the user to set the value of the main gear corresponding to each of the plurality of sub-gear stages, the value of the main gear corresponding to each of the plurality of sub-gear stages is set. The correspondence between each of the multiple sub-gear stages and the corresponding main gear stage values, as set via the graphical user interface, is stored in a memory device. When the aforementioned sub-gear stage is switched, the main gear stage is set to the value corresponding to the switched sub-gear stage based on the aforementioned correspondence relationship, A program that causes a computer to execute something.

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